SEMPARIS – Séminaires en région parisienne Séminaire commun

SEMPARIS – Séminaires en région parisienne
http ://string.lpthe.jussieu.fr/semparis/
Séminaire commun de physique
statistique LPT - LPTMS, Orsay
Jeudi 22 Novembre 2007, 14 :00
LPTMS, batiment 100, salle 201
Domaines : cond-mat.stat-mech
Titre : Entropy of randomized network ensembles
Orateur : Ginestra Bianconi ( ICTP Trieste )
Résumé : Randomized network ensembles are the null models of real networks
and are extensively used to compare a real system to a null hypothesis. In this
talk we study network ensembles with the same degree distribution, the same
degree-correlations and the same community structure of any given real network. We characterize these randomized network ensembles by their entropy,
i.e. the normalized logarithm of the total number of networks which are part
of these ensembles. We estimate the entropy of randomized ensembles starting from a large set of real directed and undirected networks. We propose
entropy as an indicator to assess the role of each structural feature in a given
real network.We observe that the ensembles with fixed scale-free degree distribution have smaller entropy than the ensembles with homogeneous degree
distribution indicating a higher level of order in scale-free networks.